Avoid collison with error(), clean up code a bit.

[tcpdump] / print-nflog.c

diff --git a/print-nflog.c b/print-nflog.c
index adeecd39ba443739c045f7625e7cec5babf52158..a29b930cb30f25ea4c01a57cc34efb9c1208a484 100644 (file)
--- a/print-nflog.c
+++ b/print-nflog.c
@@ -31,26 +31,21 @@
 
 #include <tcpdump-stdinc.h>
 
-#include <stdio.h>
-#include <pcap.h>
-
-#include "netdissect.h"
 #include "interface.h"
 
-#include "nflog.h"
-
-#ifdef DLT_NFLOG
-
-#define NFULA_PAYLOAD 9
+#if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
+#include <pcap/nflog.h>
 
 static const struct tok nflog_values[] = {
        { AF_INET,              "IPv4" },
+#ifdef INET6
        { AF_INET6,             "IPv6" },
-       { 0,                            NULL }
+#endif /*INET6*/
+       { 0,                    NULL }
 };
 
 static inline void
-nflog_hdr_print(struct netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
+nflog_hdr_print(netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
 {
        ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
 
@@ -70,13 +65,13 @@ nflog_hdr_print(struct netdissect_options *ndo, const nflog_hdr_t *hdr, u_int le
 }
 
 u_int
-nflog_if_print(struct netdissect_options *ndo,
+nflog_if_print(netdissect_options *ndo,
                           const struct pcap_pkthdr *h, const u_char *p)
 {
        const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
        const nflog_tlv_t *tlv;
-       u_int16_t size;
-       u_int16_t h_size = sizeof(nflog_hdr_t);
+       uint16_t size;
+       uint16_t h_size = sizeof(nflog_hdr_t);
        u_int caplen = h->caplen;
        u_int length = h->len;
 
@@ -86,53 +81,74 @@ nflog_if_print(struct netdissect_options *ndo,
        }
 
        if (!(hdr->nflog_version) == 0) {
-               ND_PRINT((ndo, ", NFLOG version mismatch: %u", hdr->nflog_version));
+               ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
                return h_size;
        }
 
        if (ndo->ndo_eflag)
                nflog_hdr_print(ndo, hdr, length);
 
+       p += sizeof(nflog_hdr_t);
        length -= sizeof(nflog_hdr_t);
        caplen -= sizeof(nflog_hdr_t);
-       p += sizeof(nflog_hdr_t);
 
-       do {
+       while (length > 0) {
+               /* We have some data.  Do we have enough for the TLV header? */
+               if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
+                       /* No. */
+                       ND_PRINT((ndo, "[|nflog]"));
+                       return h_size;
+               }
+
                tlv = (const nflog_tlv_t *) p;
                size = tlv->tlv_length;
-
                if (size % 4 != 0)
                        size += 4 - size % 4;
 
-               h_size = h_size + size;
-
-               /* wrong size of the packet */
-               if (size > length || size == 0)
+               /* Is the TLV's length less than the minimum? */
+               if (size < sizeof(nflog_tlv_t)) {
+                       /* Yes. Give up now. */
+                       ND_PRINT((ndo, "[|nflog]"));
                        return h_size;
+               }
 
-               p += size;
-               length = length - size;
-               caplen = caplen - size;
+               /* Do we have enough data for the full TLV? */
+               if (caplen < size || length < size) {
+                       /* No. */
+                       ND_PRINT((ndo, "[|nflog]"));
+                       return h_size;
+               }
 
-       } while (tlv->tlv_type != NFULA_PAYLOAD);
+               if (tlv->tlv_type == NFULA_PAYLOAD) {
+                       /*
+                        * This TLV's data is the packet payload.
+                        * Skip past the TLV header, and break out
+                        * of the loop so we print the packet data.
+                        */
+                       p += sizeof(nflog_tlv_t);
+                       h_size += sizeof(nflog_tlv_t);
+                       length -= sizeof(nflog_tlv_t);
+                       caplen -= sizeof(nflog_tlv_t);
+                       break;
+               }
 
-       /* dont skip payload just tlv length and type */
-       p = p - size + 4;
-       length += size - 4;
-       caplen += size - 4;
-       h_size -= length;
+               p += size;
+               h_size += size;
+               length -= size;
+               caplen -= size;
+       }
 
        switch (hdr->nflog_family) {
 
        case AF_INET:
-                       ip_print(ndo, p, length);
+               ip_print(ndo, p, length);
                break;
 
-#ifdef INET6
+#ifdef AF_INET6
        case AF_INET6:
                ip6_print(ndo, p, length);
                break;
-#endif /*INET6*/
+#endif /* AF_INET6 */
 
        default:
                if (!ndo->ndo_eflag)
@@ -140,11 +156,11 @@ nflog_if_print(struct netdissect_options *ndo,
                                length + sizeof(nflog_hdr_t));
 
                if (!ndo->ndo_suppress_default_print)
-                       ndo->ndo_default_print(ndo, p, caplen);
+                       ND_DEFAULTPRINT(p, caplen);
                break;
        }
 
        return h_size;
 }
 
-#endif /* DLT_NFLOG */
+#endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */